1. Field of the Invention
Embodiments of the invention relates to a display device, and more particularly, to a color filter substrate for a liquid crystal display device and a method of fabricating the same. Although embodiments of the invention are suitable for a wide scope of applications, they are particularly suitable for obtaining a color filter substrate for a liquid crystal display device and a method of fabricating the same that prevent a gravity defect and a touch defect.
2. Discussion of the Related Art
The importance of electronic displays is growing in today's information society, and various types of electronic displays have been extensively used in various industrial fields. The electronic display field has been developing more and more, and electronic displays that have improved performance capable of satisfying various demands of information society have continuously been developed.
Generally, an electronic display is an apparatus for visually transmitting a variety of information to humans. The electronic display is an electronic device that converts electronic information signals output from various types of electronics to light information signals that are capable of being recognized by the human eye. An electronic display may be considered as a bridging device for connecting humans to the electronic machines.
Of the electronic displays, a display device for displaying a light information signal using light emission is called a light emitting display device, and another display employing light modulation by means of reflection, scattering, and interference is called a light receiving display device. Examples of light emitting display devices, which also are referred to as active display devices, are a cathode ray tube (“CRT”) device, a plasma display panel (“PDP”) device, an organic electroluminescent display (“OELD”) device, and a light emitting diode (“LED”) device. In addition, examples of light receiving displays, which also are referred to as passive display devices, are a liquid crystal display (“LCD”) device and an electrophoretic image display (“EPID”) device.
Light emitting display devices have been applied to televisions and computer monitors. The cathode ray tube (“CRT”), which is the display having the longest history, has a large market share in terms of economic efficiency, but has many disadvantages, including heavy weight, large volume, and high power consumption. With the recent trend of voltage reduction and electric power reduction of electronic devices based on rapid advances in semiconductor technology and the recent trend toward miniaturized, slim, and light electronic machines, the demand for flat panel displays as electronic displays that are suitable for novel environments is rapidly growing.
To satisfy the demand, flat panel displays, such as a liquid crystal display (“LCD”) device, a plasma display panel (“PDP”) device and an organic electroluminescent display (“OELD”) device, has been developed. Of the flat panel displays, the liquid crystal display device, which is small, light, and slim and has low power consumption and low driving voltage, is being watched.
In a liquid crystal display device, a liquid crystal material having anisotropic dielectricity is formed between a color filter substrate on which a color filter and a black matrix are formed and an array substrate on which a thin film transistor (“TFT”) component and a pixel electrode are formed. An LCD device also includes a common electrode, which is formed on one of the color filter substrate and the array substrate. Different electric potentials are applied to the pixel and common electrodes to control the intensity of an electric field. Such an electric field changes the molecular arrangement of the liquid crystal material, thereby controlling the intensity of light penetrating the color filter substrate and the array substrate, resulting in the display of desired images.
In general, a spacer is formed between the color filter substrate and array substrate of the liquid crystal display device to maintain a cell gap constant, and the spacer may be a ball spacer having a spherical shape disposed on the substrate. The ball spacer is easy to use even under a certain temperature condition because it has an expansion coefficient similar to that of the liquid crystal material depending on a temperature change. However, the ball spacer is moved when vibration or shock is applied to the liquid crystal display device, thereby distorting the liquid crystal orientation. This causes light leakage, resulting in a decrease in the contrast ratio of the liquid crystal display device.
An alternative for solving this problem is a method of forming a column spacer patterned on a substrate, instead of a ball spacer. The column spacer can be formed at a desired position of a substrate to prevent light leakage caused by dispersion and does not move. For example, the column spacer can be formed on one of the array substrate and the color filter substrate. In the manufacturing process of a liquid crystal display device, an array substrate and a color filter substrate undergo their respective procedures and thereafter are bonded to each other. Thus, it is possible to keep production in line with the array substrate by forming a column spacer on a color filter substrate that undergoes a relatively simple procedure.
However, a liquid crystal display device with a column spacer still experiences problems like a gravity defect, in which liquid crystals are concentrated in a downward gravity direction under a high temperature environment, or a touch defect, which is caused by a pressure applied to the liquid crystal display.